Yes, that's true. Unfortunately, young or middle-aged women were sometimes accused of witchcraft too. But most of the time, a witch is old, I think.

This is not related to folkore such as we are discussing here, but it's a good thing to be aware of: the religious page of my newspaper had an article by a minister who visited a village in Ghana to which women accused of witchcraft are banished. I can't recall all the pathetic reasons for which women are banished, but here's one I recall clearly:

A woman can be labelled a witch and driven from her village and her family if people around her get sick from something, but she doesn't.

Isn't that terrible? Other villagers might have eaten some spoiled food which she didn't eat, but the villages don't know anything about microbes and food poisoning, and so she loses her home and family. Or the other villagers might have suffered a viral infection to which she had already developed immunity.

Stories like this make you realize the value of education.